As long as the roads aren't snow and ice covered, I'll ride. There's been a couple of days that were below 0 degF and several in the single digits. Heated clothing makes this not only possible, but comfortable. If it gets well below freezing, I also have thin polypropolene hooded mask (don't know what else to call it) that I wear inside my helmet.

How cold can I go?  Depends on how cold it can get, I guess.  I've been riding an hour to work in 20-22 F for a couple of weeks now.  I've got the clothes figured out, but as someone said, the ice on the inside of the face shield is a pain.  I need to find a way to stop that.

I also need to find some studded tires, because we generally get a little snow around here in the winter.

Heck, if I didn't ride below 45 F, I'd have 9 miles on my bike this summer instead of 9000.

Last December 23rd I rode from Owatonna, MN to Ames, IA straight down I35 @ 75mph (2hrs driving).  For half the trip I was followed by my fiance, and the temp her car read was 8deg F.

That was by far the coldest (and subsequently longest!) ride I've ever done.  Even I thought that was a little stupid...

Wow!  I'm impressed, many brave souls out there.  More power to you!

Ess:  Sorry man, I love cold weather, however, riding in the cold is something I could do without.  

I've ridin' in 4 Santa Claus parades and braved two snow storms. That was a few years ago.

Coldest ride was 28 degrees, dry roads, on a KLR650. I was so layered that I was actually a little warm; except for my fingers and toes. I looked like the Michelin man.
Routinely ride into the 30's as long as there's no moisture on the roads; but I've not attempted that type of riding on the Savage yet. Not sure how that air cooled thumper will react to cold, cold air.

It's been hoovering aound freezing in the mornings around here and I'm still riding to work. As long as the roads are not icy I'll still ride. At this time of year, every ride is a bonus ride!!! I just picked up gloves that have thinsulate and they are working real good. They also have large cuffs that stop wind going up the sleeves. We used to go back country  riding on Trimotos when it was -20. These machines were air cooled singles (250cc) and never had any problems, so I would assume the Savage will have no issues in the cold either. At my age now, it would be my joints that will have the issues at -20.

Coldest was 16 degrees under dry conditions.  But as long as there isn't any ice I'll be riding.